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The acceptance and deployment of electric power from sustainable sources, which are less polluting than fossils, have been a consensus throughout society. Specially, the growth of the installed capacity in photovoltaic energy has been considerable in distributed generation. In order to properly take advantage of this growing demand, it is necessary to adopt appropriate measures and procedures to improve the operation and performance of photovoltaic systems. The purpose of this work is to present such measures and procedures, under quantitative and qualitative analysis, using scientific methodologies and tools. In the end, a set of procedures was obtained that analyzes functional and structural aspects of small grid-connected photovoltaic systems. Its validation was carried out in a case study of photovoltaic system of the Department of Electrical Engineering (DELT) of the Federal University of Parana (UFPR, Brazil).

The authors have proposed an image-memory LCD using ferroelectric thin film for memory elements to achieve ultralow power consumption. Memory operation with gray-scale levels was confirmed by using an equivalent circuit model of the LCD consisting of a discrete ferroelectric device. The reduction in power consumption is related to hold time and the ferroelectric characteristics.

Nonlinear V-I characteristics were observed in semiconductive BaTiO3 film heated at 550 °C for 2 h in air. The temperature dependency of the resistivity appeared to be the minimum near 120 °C for this heat treatment. It was estimated from the keeping time dependency of the resistivity that the oxidation in this film occurs first at the grain boundary between columnar grains and then goes to the inner of the grains. The structure made up of both the semiconductive grains and the oxidized interfaces with high resistivity was considered to generate these properties. Nonlinear V-I characteristics also appeared from diffusion of Bi element from the surface of the BaTiO3 film. These results show the possibility of the generation of new properties by the modification of grain boundaries between columnar grains of semiconductive BaTiO3 film, which is comparable to that of the sintered body of semiconductive BaTiO3-based functional ceramic.

Submicron semiconductive epitaxial BaTiO3 thin film was prepared on (100) MgO substrate. An epitaxially grown BaTiO3 film prepared by MOCVD was coated with ethanol solution of LaCl3 and heated under a reducing atmosphere at 800-1200°C. The resistivity was less than 1Ω·cm and the carrier concentration was in the order of 1018cm-3. The film was n-type semiconductor and the resistivity increased abruptly with the increase in temperature above 600°C in air because of the decrease of the carrier concentration.

We have made a prototype of flexible display system integrated with bend-input function. It consists of flexible display, flexible backlight unit with bending sensor, and MPU connected to PC. Zooming in/out in Google Earth and paging up/down in PDF files have been successfully done by bending the flexible display.

A novel formation process for TFT using our proposed novel selective transfer technique, which enables low cost TFT fabrication on a large and flexible substrate, is proposed. This technique is used to fabricate a 3.2-inch LCD Panel using amorphous silicon TFT transferred on glass substrate for the first time.

A 2.8″-diagonal reflective image-memory LCD using ferroelectric film for memory elements, which enables ultra-low-power consumption, is fabricated on a glass substrate for the first time. The asymmetrical feature of the hysteresis loop is improved by symmetrical ferroelectric capacitor configuration, and achieved an image-memory color LCD with good quality.

Lead-zirconate-titanate (PZT) thin films were prepared on non-alkaline glass substrates widely used in liquid crystal display (LCD) devices, by plasma-assisted magnetron RF sputtering with an immersed coil. After preparation of the PZT thin film, the glass was available for use in LCD device processing. No mutual diffusion of the elements was recognized between the glass substrate and the bottom electrode. The PZT layer had a dense film structure with rectangular and columnar grains, and only its perovskite phase was crystalline. PZT thin films on a glass substrate had leakage current densities of about 10-8 A/cm2, acceptable hysteresis loop shapes with the remanent polarization (P r ) of 45 µC/cm2 and the coercive field (E c ) of 90 kV/cm. Ferroelectric properties on a glass substrate almost conform with those on a Si-based substrate.

A novel plasma-assisted RF magnetron sputtering system with an immersed coil antenna between a target and a substrate was applied for preparing Pb(Zr, Ti)O3 (PZT) thin films. The antenna enabled the generation of inductively coupled plasma (ICP) independently of the target RF source. The plasma assisted by the antenna resulted in the changes of ion fluxes and these energy distributions irradiating to the substrate. The crystalline phase of the deposited PZT thin films was occupied by the perovskite phase depending on the antenna power. In addition, a high deposition rate, modified uniformity of film thickness, and a dense film structure with large columnar grains were obtained as a result of effects of the assisted plasma. The application of the plasma-assisted sputtering method may enable the preparation of PZT thin films that have excellent properties.

A novel image-memory LCD using ferroelectric film for memory elements with gray-scale capability and ultra-low-power consumption has been proposed. We have demonstrated the operation of image-memory function by using an LC cell with discrete ferroelectric devices. A gray-scale image without any power consumption for more than several seconds has been obtained.

Racemic Grignard reagents, 2-phenylpropylmagnesium chloride and 2-norbornylmagnesium chloride were kinetically resolved by asymmetric cross-coupling with vinyl bromides in the presence of chiral phosphine-nickel catalysts to give optically active coupling products (~37% ee) and carboxylic acids after carbonation with carbon dioxide.